
I-98
EPSON
S1C62740 TECHNICAL HARDWARE
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (A/D Converter)
ADRS0, ADRS1:
Resolution selection
(F3HD0, D1)
Selects the A/D conversion resolution (number of counts).
ADRS1
ADRS0
Resolution
Conversion time
0
6,552 counts
500 msec
0
1
3,276 counts
250 msec
1
0
1,638 counts
125 msec
1
820 counts
62.5 msec
At initial reset, these registers are set to "0".
AIS0–AIS3, AI0–AI4:
Measurement items selection,
Analog input terminal selection
(F4HD0–D3), (F5H, F6HD0)
Selects the measurement item and terminal that does the analog
input, by a combination of these registers.
Table 4.12.7 Specification of the analog input terminal and measurement items
AIS3 AIS2 AIS1 AIS0
AI4
AI3
AI2
AI1
AI0
Measurement items
00000
0
01
AI0 voltage measurement (GND reference)
00000
0
10
AI1 voltage measurement (GND reference)
00000
0
1
00
AI2 voltage measurement (GND reference)
00000
1
0
00
AI3 voltage measurement (GND reference)
00001
0
00
AI4 voltage measurement (GND reference)
00010
0
11
AI1 differential voltage measurement (AI0 reference)
00100
1
00
AI3 differential voltage measurement (AI2 reference)
01001
0
1
00
AI2 resistance measurement (AI4 reference)
10001
1
0
00
AI3 resistance measurement (AI4 reference)
One combination can be selected from within Table 4.12.7. Do not
set a value other than those indicated in Table 4.12.7.
At initial reset, these registers are set to "0".
ADON:
A/D converter control
(F6HD3)
Turns the A/D converter ON/OFF and resets it.
When "1" is written: ON and reset
When "0" is written: OFF
Reading: Valid
When the A/D converter is in the stop status, the A/D converter
goes ON and starts A/D conversion by writing "1" into the ADON.
When it writes "1" into the ADON during the A/D conversion
operation, it then stops the A/D conversion cycle and shifts to a
new A/D conversion (from auto zero adjustment) cycle.
It terminates the A/D conversion at the point where it writes "0"
into the ADON and turns the A/D converter circuit OFF.
You should set the A/D converter to OFF when it is not necessary,
in order to reduce current consumption.
At initial reset, this register is set to "0".
Table 4.12.6
Resolution selection